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美国Cytoskeleton公司细胞骨架研究相关产品
罗丹明标记鬼笔环肽，Rhodamine Phalloidin货号：PHDR1
Product Uses Include
- Fluorescent staining of actin filaments in fixed tissue sections and tissue culture cells preparations. Note: Unlike many actin antibodies, Acti-stain™ 488 phalloidin binds only to F-actin resulting in low background fluorescence. Furthermore, binding of F-actin by Acti-stain is not appreciably different between species.
- Preparation of stabilized fluorescent actin filaments in vitro.
Actin staining is very useful in determining the structure and function of the cytoskeleton in living and fixed cells. The actin cytoskeleton is a very dynamic and labile structure in the living cell, but it can be fixed with paraformaldehyde prior to probing or staining for actin structures.
Material
Phalloidin is a seven amino acid peptide toxin from the mushroom Amanita phalloides, which binds specifically and with high affinity (Kd 20 nM) to the polymerized form of actin (F-actin). Phalloidin lowers the critical concentration of actin polymerization to less than 1 µg/ml, thereby acting as a polymerization enhancer. Phalloidin has been labeled with a proprietary green fluorescent dye which allows it to be used to stain actin filaments in tissue cultured cells and tissue sections (1, see Figure 1) and cell-free preparations. Acti-stain™ 488 phalloidin-labeled actin filaments retain many functional characteristics of unlabeled actin including their ability to interact with myosin. Actin-stain™ 488 phalloidin is supplied as an orange solid.
Note: Phalloidin is toxic and must be handled with care (LD50 human = 2mg/Kg).
Example Results and Specifications
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| Figure 1. Actin Stress Fibers stained with Acti-stain™ 488 in a Swiss 3T3 cell. |
| Figure 2. Emission and excitation scans for Acti-stain™ phalloidins | |
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| Swiss 3T3 cell stained with anti-vinculin (red), Dapi (blue nucleus) and F-actin is stained with Acti-stain™ 488 (green F-actin, Cat.# PHDG1). | Absorbance and fluorescence scan of Acti-stain™ 488. Labeled phalloidin was diluted into methanol and its absorbance and excitation spectra were scanned between 350-750 and 500-750 nm, respectively. Absorbance peaks at 500 nm and fluorescence at 550 nm. |
Acti-stain phalloidins are the most well characterized phalloidins available. Tabe 1 describes their brightness, photostability, background and affinity constants to F-actin. Compare these performance characteristics to other fluorescent phalloidins and you will see the advantages of using Acti-stain™ for your actin staining requirements.
Table 1. Biochemical characteristics of fluorescent phalloidins
| Conjugate | Cat.# | Wavelengths (Ex/Em) | Brightness (AFU*) | Stability to photobleaching(half life in seconds**) | Background (% of total AFU at 100nM**) | Affinity (Kd in nanomolar) |
| Fluorescein-phalloidin | na | 485/535 FITC filter set | 432 | 6 | 22 | 72 +/-12 |
| Acti-stain™ 488 | PHDG1 | 485/535 FITC filter set | 832 | 57 | 5 | 55 +/-8 |
| Acti-stain™ 535 | PHDR1 | 535/585 TRITC filter set | 430 | 27 | 12 | 36 +/-7 |
| Acti-stain™ 555 | PHDH1 | 535/585 TRITC filter set | 551 | 46 | 16 | 63 +/-8 |
| Acti-stain™ 670 | PHDN1 | 640/680 Cy5 filter set | 332 | 8 | 18 | 50 +/-12 |
* = AFU's measured by quantitative cell imaging. ** = Measured in stained Swiss 3T3 cells in the absence of antifade.
References
1. Wulf, E. et al. (1979). Proc Natl Acad Sci USA. 76(9):4498-4502.
2. Kron, S.J. et al. (1991). Meth. Enzmol. 196: 399-416
Roitbak et al., 2011. The role of microRNAs in neural stem cell supported endothelial morphogenesis. Vascular Cell. v 3, p 25.
Yuan et al., 2012. Subsecond absolute quantitation of amine metabolites using isobaric tags for discovery of pathway activation in mammalian cells. Anal. Chem. v 84, pp 2892–2899.
